Until relatively recently, network operators built and configured their networks to carry voice traffic only. Each residential subscriber needed one telephone line at the most, and it was used for speech. By the end of the 20th century, fixed and mobile telephony and data communication had evolved largely existing in separate worlds of networks. These worlds shared the same types of transmission facilities and a growing part of the telephony traffic was constituted by dial-up Internet access. Broadband access mostly occurred as high-speed data circuits for large enterprises.
Each of these known networks has its own management systems, its own resources for switching, transport and access, and its own terminal types. Each operator takes responsibility for everything in the supply chain, from subscriber access to service creation and delivery across a fully owned network infrastructure.
However, network operators are challenged by increasing end-user demands. An end-user wants to phone, e-mail, surf, download, stream, and conference at all times of the day and at the same time. Simultaneously, the number of operators are increasing and the competition between operators has increased.
When a user wants to establish a communication channel, e.g. to make a telephone call, conduct a video conference, watch a movie, play a game, chat, search databases, etc, the user typically requests the operator of the network to which he is a subscriber, in the following the first network, to establish and maintain a communication channel between the user and the desired other participants in the requested communication session. The specific operator may however route the data of the communication through other operators' networks, in the following designated second networks. Typically, the operator of the first network selects the second network based on geographical position of the communication participants, the type of service, desired quality of service, and cost.
The competition is most evident in the multiplicity of services and tariffs from each network operator. The tariffs vary not only between destinations but also according to the nature of the contract signed between the subscriber and the operator, the time of day, the duration of the communication, the data rate, the amount of data transferred, the type of data, method of payment, promotions, etc.
Thus, the increasing number of operators, services, complex tariff structures, and different levels of quality of service have created a need for a system for automatic selection of networks for appropriately routing of the data or information of the requested communication session.
The operators compete on business parameters, such as cost, quality, service, interconnect agreements, security, etc. An operator's income is generated by a number of different sources. Income from the connectivity layer is generated by taxation of the media stream, e.g. the transmitted amount of data, the reservation of necessary resources, etc. By careful selection of the second network for connectivity based on business parameters, the operator can increase his profit.
In WO 00/02400 a routing network for use in a telecommunications network is disclosed, comprising a plurality of networks, and in which said routing network has at least one switch for routing traffic to a required destination via another network according to a routing table. The routing network has call routing data management means including: means for monitoring a plurality of parameters associated with the other networks in the telecommunications network; means for determining a routing table for each switch in said network based on the monitored parameters; and, means for controlling the switch or switches according to the determined routing table.
FIG. 1 schematically illustrates a prior art set-up of a communication channel for a communication session. In this example, the communication session is a telephone conversation. The networks 1–5 are IP networks or ATM networks. At the start of the session, session control communication channel 6 is set up, e.g. including negotiation of codec and exchange of connection points. Next, the data payload communication channel 7 or connectivity path 7 is set up as a bearer for transport of the media stream. The boarder elements 8 that reside at the edge of the respective networks establish the bearer 7. The best effort method may be used, or, routing tables for a label switch router may be manually configured.
In a multi-protocol label switching (MPLS) architecture, the boarder elements 8 of FIG. 1 are considered to be ingress/egress nodes. The networks 1–5 contain a number of label switch routers, and a label distribution protocol (LDP) is used to exchange routing information. Constraint based routing within a MPLS network can secure a bandwidth or other service class characteristics of a trunk, but it cannot secure corresponding resources for an individual communication session. Furthermore, MPLS does not provide means for selection of networks in accordance with criteria defined in the first network.